P0300 random misfire

on my 99 tahoe 4wd ( about 150k miles), my engine light went on and got this code, also a couple weeks ago, it was saying bank 1 to rich..
spark plug are only a couple months old.
what could cause the misfire? ( before changing the plugs I also had the random misfire code show up then went away as I changed the plugs)

on my 99 tahoe 4wd ( about 150k miles), my engine light went on and got this code, also a couple weeks ago, it was saying bank 1 to rich..
spark plug are only a couple months old.
what could cause the misfire? ( before changing the plugs I also had the random misfire code show up then went away as I changed the plugs)

Click to expand...

Trouble Code...P0300.....a Random Misfire, may mean that one or more of the following has happened

I don't remember the brand, they may be bosh, ill have to look.
I must say that I don't like your list.......
I changed the o2 sensors a couple months ago.
That truck has a throttle body spacer and magnaflow exaust (was like this when I bought it)

I don't remember the brand, they may be bosh, ill have to look.
I must say that I don't like your list.......
I changed the o2 sensors a couple months ago.
That truck has a throttle body spacer and magnaflow exaust (was like this when I bought it)

Click to expand...

Regarding which Spark plugs you installed......The Vortec Engines Run And Perform Better when A/C Delco Plugs are installed, and the ones you want are the......A/C Delco Platinum Spark Plugs......with the Bosh plugs, that may be why you are getting a Random Misfire.